Cisco Cisco Email Security Appliance C160 Mode D'Emploi

message, and “false” if it is not found. For example, the following example checks to see if the header 

X-Sample

 is found, and if its value contains the string “

sample text

”. If a match is made, the message 

is bounced.

You can specify non-ASCII characters to search for in the value of the header.

The following example demonstrates the header rule without a comparison. In this case, if the header 

X-DeleteMe

 is found, it is removed from the message.

When working with headers, remember that the current value of the header includes changes made 
during processing (such as with filter actions that add, remove, or modify message headings). See 

 for more information.

The 

random

 rule generates a random number from zero to N-1, where N is the integer value supplied in 

parenthesis after the rule. Like the 

header()

 rule, this rule may be used in a comparison, or may be used 

alone in a “unary” form. The rule evaluates to 

true 

in the unary form if the random number generated 

is non-zero. For example, both of the following filters are effectively equal, choosing Virtual Gateway 
address A half the time, and Virtual Gateway address B the other half of the time: 

FooHeaderFilter:

   if (header('X-Sample') == 'sample text')

   {

        bounce();

   }

DeleteMeHeaderFilter:

   if header('X-DeleteMe')

   {

        strip-header('X-DeleteMe');

   }

load_balance_a:

   if (random(10) < 5) {

        alt-src-host('interface_a');

   } else {

        alt-src-host('interface_b');

   }